1. Field of the Invention
This invention relates to drilling platforms in general and drilling platform assemblies in particular.
2. Prior Art
Drilling platforms typically include a one or more box support members. The box support members are usually rectangular steel frameworks. Two or more box support members will often be stacked one upon the other until a desired height is reached. These box supports will be arrayed in parallel columns, leaving a gap between them. The gap will generally include the center line of the well being drilled or serviced. Thus, it is important that the support structure not obstruct the center line of the well. However, it is equally important that the structure be capable of supporting the tools and equipment that are used to work over the well.
To provide the requisite support while leaving the desired gap open, spreader beams spanning the gap are used to connect the parallel columns of box support members. The spreader beams are typically substantial steel girders. Together the spreader beams and the box support columns create a foundation on which a drilling or work platform may be constructed. Once the foundation is in place, heavy oil field equipment may be supported upon the platform.
Spreader beams are currently installed using a system of driven pins and apertures. Holes are contained in each end of the spreader. Matching holes are provided in the box support members. Spreader beams are raised into place with a crane. The holes must be physically aligned by workers who then drive the pins. There is very little tolerance for error in this process, as the alignment of the apertures must be precise. The necessary precision makes for tedious and repetitive adjustments with a crane, raising and lowering the spreader beams until the apertures are aligned precisely. While this is taking place, the workers driving the pins must be in the vicinity of the apertures to guide the crane operator and to physically guide the spreader beams into place. The required proximity of the workers to and frequent physical contact with the moving steel girders places the workers at risk for injury.
Drilling rigs are typically rented by the day, at rates of many thousands of dollars per day and up. Thus, excessive amounts of time spent constructing the platform foundation can be costly. Additionally, the high labor requirements of prior art platform construction increases the cost of erecting drilling and service rigs. Therefore, a drilling platform and methods of erecting the same meeting the following objectives is desired.